What is object-oriented programming?

The meaning of the term `object oriented' is examined in the context of the general-purpose programming language C++. This choice is made partly to introduce C++ and partly because C++ is one of the few languages that supports data abstraction, object-oriented programming, and traditional programming techniques. The support of programming paradigms by languages is discussed and four paradigms are examined: procedural, data hiding, data abstraction, and object-oriented programming. The support of the latter two by C++ is discussed in some detail     

面向对象软件度量工具的软件结构

利用软件度量工具度量程序源码的各类质量属性是提高程序质量的一个重要方法．目前,面向对象语言已逐渐成为主流编程语言,度量基于对象技术的软件成为必然的需求．然而,由于面向对象语言数目众多,许多面向对象语言又都在发展中,用户所需要的度量也不尽相同,各种分散的需求对度量工具的灵活性与通用性提出了挑战．首先给出了一个适用于ＯＯ语言软件度量工具的一个灵活的软件结构,然后在分析了各类软件度量的基础上,解析了该结     

A new programming paradigm for engineering design software

Currently available programming and database systems are insufficient for engineering applications. The authors contend that a logical progression from a formal conceptual model of the engineering domain to a computational model will lead to new programming paradigms capable of directly supporting engineering applications in a rigorous, concise manner. A formal domain model devised by the authors, theHybrid Model (HM) of design information, is briefly introduced. It is an extension of axiomatic set theory and is discussed in detail elsewhere. HM forms the basis ofDesigner, a prototype-based object-oriented programming language supporting a signature-based canonical message-passing mechanism and multiple inheritance. Designer is implemented using the Scheme programming language. Because Designer satisfies a formal conceptual model, and because it is based on a formally specified language, its robustness and logical validity are superior to those of other languages not founded on formal principles. Designer combines concepts of functional and object-oriented programming to provide the formal rigor and flexibility to capture the complex and strongly interrelated information that designers use. Examples demonstrate how Designer represents design information. The results of the authors' research indicate that Designer can capture design information (including aspects of functional requirements and design intent) effectively and efficiently.     

支持面向对象技术的设计模板

设计模板是面向对象设计的新的概念。它抽象了面向对象设计中的经验知识，通过组织对象之间的关系，定义特定的软件结构。由于模板的可重用性，它的应用可以大大减少设计的复杂度。本文给出设计模板的综述介绍，给读者提供一个整体的印象。     

Introduction to object-oriented systems engineering.1

Within software development, object-oriented (OO) analysis provides an incremental and iterative approach to guide the requirements definition, design, and development of software-intensive systems. OO analysis uses the Unified Modeling Language (UML) to capture and represent these requirements. UML permits specification of the product independent of programming language or development process. This independent product representation has raised interest in the systems engineering community: OO methods might be a mechanism to unite product development disciplines and remove the gap between the specified and as-built products. The paper discusses the object oriented systems engineering process.     

External relationships of objects

External relationships of objects represent semantic dependencies between objects that enable inter-object communication and augment the services the objects provide with role-specific behaviors. Most of the object-oriented design methodologies support the notion of external relationships at the conceptual level, but OO programming languages have no language construct to directly implement the external relationships, which are implemented as containment relationships with embedded pointers resulting in the semantics of the relationships being buried in code. Moreover, object-oriented programming languages lack a mechanism to allow a dynamic classification of objects according to the roles they play in external relationships. This paper describes a technique to treat an external relationship as a conceptually useful abstraction at the specification stage and a separately identifiable structure at the implementation stage, by providing a declarative specification and an implementation in C++ with special focus on the implementation of object roles. © 1998 John Wiley & Sons, Ltd.     

Implementing design patterns as parametric aspects using ParaAJ: The case of the singleton,observer, and decorator design patterns

Implementation of a design pattern can take many forms according to the programming language being used. Most of the literature presents design patterns in their conventional object-oriented implementations. Several other studies show the implementation in aspect-oriented languages such as AspectJ, EOS, and Caesar. In this work, we compare the implementation of three design patterns: singleton, observer, and decorator design patterns in these languages and also discuss the possibility of implementing them in ParaAJ: an extension to the AspectJ language that implements the idea of parametric aspects. We found that ParaAJ helps in making the implementation of the singleton and observer patterns reusable but it fails to help in the decorator case. The problem with the decorator pattern exists because of the current translation mechanism of ParaAJ׳s aspects to normal AspectJ׳s aspects. This opens the door for further work in ParaAJ to better support the idea of parametric aspects.     

The Implementation of a Deductive Query Language Over an OODB

The ROCK and ROLL database system cleanly integrates deductive and object-oriented capabilities by defining an imperative programming language, ROCK, and a declarative, deductive language, ROLL, over a common object-oriented (OO) data model. Existing techniques for evaluation and optimization of deductive languages fail to address key requirements imposed by ROLL such as: strict typing; placement of deductive methods (predicates) within classes; encapsulation; overriding and late binding. This paper describes the task of implementing an evaluator and optimizer for ROLL, explaining how existing implementation techniques for deductive languages were adapted to meet these requirements and extended to support novel types of optimization.     

MODELS AND TRENDS IN PARALLEL PROGRAMMING

This paper introduces and discusses programming models for parallel processing and recent trends in the area of parallel programming. The paper discusses different parallel programming languages and tools that reflect various parallel computation models. These language differ in expressiveness, portability and performance. Software design and implementation largely varies by using different languages that make the programmer task easy or complex. We describe here the design goals and the main issues of parallel programming models and languages belonging to the following categories: shared-space based languages, message-based languages, parallel toolkits, data-parallel languages, parallel declarative languages, parallel object-oriented languages, and parallel composition-based languages. Tools and languages such as HPF, Linda, Java, OpenMP, PVM, MPI, Parallel C+ +, Sisal, Orca, Mentat, SkieCL, BSP and others are described in some detail. Their main features for design and implementation of high performance applications are discussed. Finally, we outline directions of research and development in the parallel programming area with a special attention to novel approaches based on high-level programming structures that make transparent to the users the architectural details of parallel computing machines.     

The object-oriented functional data language

The object-oriented functional data language (O²FDL) is an interactive strongly typed database programming language that integrates the object-oriented and functional programming paradigms. It was designed for advanced applications that require a powerful and uniform database programming language supporting the software engineering principles of these tow paradigms. To this end, the O² FDL supports inheritance and encapsulation of object-oriented languages, and an equational notation and strong typing of functional programming. Strong typing is extended with type restrictions to constrain the instantiations of type variables in function interfaces, while inheritance is augmented with a monotonic subtype rule for function redefinition. The O²FDL also supports novel features. For the core of the O²FDL, a denotational semantics based on an extended λ-calculus is provided. For selected system-defined functions, operational semantics are provided and it is demonstrated that a subset of the O²FDL is at least as expressive as the relational algebra     

Antipatterns in the Creation of Intelligent Systems

A design pattern is a named problem-solution pair that enables large-scale reuse of software architectures or their components. Ideally, patterns explicitly capture expert knowledge, design trade-offs, and design rationale and make these lessons learned widely available for off-the-shelf use. They can also enhance developers' vocabulary - for example, by easing the transition to object-oriented programming. Conventionally, patterns consist of four elements: a name, the problem to be solved, the solution to the problem (often termed the refactored solution), and the consequences of the solution. Numerous sets of patterns (collectively known as pattern languages) exist for software design, analysis, management, and so on. Shortly after the notion of design patterns emerged, practitioners began discussing problem-solution pairs in which the solution did more harm than good. These have come to be known as antipatterns, and they are well known in the design and management communities     

Object-oriented analysis and design of the Message Passing Interface

The major contribution of this paper is the application of modern analysis techniques to the important Message Passing Interface standard, work done in order to obtain information useful in designing both application programmer interfaces for object-oriented languages, and message passing systems. Recognition of ‘Design Patterns’ within MPI is an important discernment of this work. A further contribution is a comparative discussion of the design and evolution of three actual object-oriented designs for the Message Passing Interface ( MPI-1SF ) application programmer interface (API), two of which have influenced the standardization of C++ explicit parallel programming with MPI-2, and which strongly indicate the value of a priori object-oriented design and analysis of such APIs. Knowledge of design patterns is assumed herein. Discussion provided here includes systems developed at Mississippi State University (MPI++), the University of Notre Dame (OOMPI), and the merger of these systems that results in a standard binding within the MPI-2 standard. Commentary concerning additional opportunities for further object-oriented analysis and design of message passing systems and APIs, such as MPI-2 and MPI/RT, are mentioned in conclusion. Connection of modern software design and engineering principles to high performance computing programming approaches is a new and important further contribution of this work. Copyright © 2001 John Wiley & Sons, Ltd.     

组态软件设计中的模式应用

组态软件作为一种在工业上被广泛应用的可配置软件，其设计面临着过多的可变因素。通过在组态软件的开发过程中引入设计模式，可以简化组态软件的结构，提高代码的复用性，并能有效应对将来可能出现的变更。本文着重讨论了Adapter、Bridge、Observer三种设计模式在组态软件设计中的应用。     

Should ML be Object-Oriented?

At a fundamental level, functional and object-oriented programming languages are all ‘higher-order’, in the sense that they support computing with values that are themselves pieces of program code encapsulated with a local environment. In functional languages these ‘active’ values are functions, while in object-oriented languages they are objects. Both styles of higher-order language claim to provide good support for writing adaptable programs, but functional and object-oriented languages achieve this adaptability in different ways: functional programs rely on parameterisation at the value, type and module level, while object-oriented languages rely primarily on subtyping and implementation inheritance. Here we compare these two approaches, mainly in terms of the features and properties of their type systems, and consider the benefits and disadvantages of unifying (or merging) the two paradigms by adding object-oriented features to ML as a base language. We argue that while some of the simpler aspects of object-oriented languages are compatible with ML, adding a full- edged class-based object system to ML leads to an excessively complex type system and relatively little expressive gain, especially if we aim to preserve that mostly functional style of programming that is a major advantage of ML. Received March 2002 / Accepted in revised form April 2002     

Design of an empirical study for comparing the usability of concurrent programming languages

Context: Developing concurrent software has long been recognized as a difficult and error-prone task. To support developers, a multitude of language proposals exist that promise to make concurrent programming easier. Empirical studies are needed to support the claim that a language is more usable than another.Objective: This paper presents the design of a study to compare concurrent programming languages with respect to comprehending and debugging existing programs and writing correct new programs. The design is applied to a comparison of two object-oriented languages for concurrency, multithreaded Java and SCOOP.Method: A critical challenge for such a study is avoiding the bias that might be introduced during the training phase and when interpreting participants’ solutions. We address these issues by the use of self-study material and an evaluation scheme that exposes any subjective decisions of the corrector, or eliminates them altogether.Results: The study template consisting of the experimental design and the structure of the self-study and evaluation material is demonstrated to work successfully in an academic setting. The concrete instantiation of the study template shows results in favor of SCOOP even though the study participants had previous training in writing multithreaded Java programs.Conclusion: It is concluded that the proposed template of a small but therefore easy-to-implement empirical study with a focus on core language constructs is helpful in characterizing the usability of concurrent programming paradigms. Applying the template to further languages could shed light on which approaches are promising and hence drive language research into the right direction.     

An empirical study of object-oriented system evolution

Software metrics have been used to measure software artifacts statically—measurements are taken after the artifacts are created. In this study, three metrics—System Design Instability (SDI), Class Implementation Instability (CII), and System Implementation Instability (SII)—are used for the purpose of measuring object-oriented (OO) software evolution. The metrics are used to track the evolution of an OO system in an empirical study. We found that once an OO project starts, the metrics can give good indications of project progress, e.g. how mature the design and implementation is. This information can be used to adjust the project plan in real time.We also performed a study of design instability that examines how the implementation of a class can affect its design. This study determines that some aspects of OO design are independent of implementation, while other aspects are dependent on implementation.     

If Prolog is the Answer, What is the Question? or What it Takes to Support AI Programming Paradigms

Knowledge programming, which makes use of the explicit representation and interpretation of knowledge to create intelligent programs, requires specialized languages and tools to help programmers. Prolog, an implementation of a logic programing language, provides some of these tools; it and other languages have been argued to be the "best" way to do such knowledge programming. This paper raises questions which suggest that any single paradigm of programming (e.g., logic programming or object-oriented programming) benefits by being integrated in a single environment with other paradigms of programming. Integration of these paradigms with each other, and within a flexible, user-friendly computing environment is also necessary. Such an environment must provide source level debugging and monitoring facilities, analysis and performance tuning tools, and an extended set of user communication programs.     

Systematic pattern selection using pattern language grammars and design space analysis

Software patterns provide reusable solutions to recurring design problems in a particular context. The software architect or designer must find the relevant patterns and pattern languages that need to be considered, and select the appropriate patterns, as well as the best order to apply them. If the patterns and pattern languages are written by multiple pattern authors, it might be necessary to identify interdependencies and overlaps between these patterns and pattern languages first. Out of the possible multitude of patterns and pattern combinations that might provide a solution to a particular design problem, one fitting solution must be selected. This can only be mastered with a sufficient expertise for both the relevant patterns and the domain in which they are applied. To remedy these issues we provide an approach to support the selection of patterns based on desired quality attributes and systematic design decisions based on patterns. We propose to formalize the pattern relationships in a pattern language grammar and to annotate the grammar with effects on quality goals. In a second step, complex design decisions are analyzed further using the design spaces covered by a set of related software patterns. This approach helps to systematically find and categorize the appropriate software patterns—possibly even from different sources. As a case study of our approach, we analyze patterns from a pattern language for distributed object middleware. Copyright © 2006 John Wiley & Sons, Ltd.     

一种面向对象的多风格语言的消息传递方式

面向对象的程序设计目前已成为大多数计算机软件系统设计的一种新趋势.本文我们提出了一种如何在面向对象的环境中通过个体间灵活的消息传递方式自然、有机地结合多种知识表示方法的途径,并结合作者提出的一种面向对象的多风格智能程序设计语言OMIPL(在 SUN/4工作站上实现)详细说明了这种消息传递方式及其相应的消息响应过程.